Saturday, May 18, 2013

So Guess What Else Is Pointing At the Earth?

As most of the readers of this blog know already, a strong and growing tendency exists in cosmology to examine critically, and possibly subject to crucial experimental test, the foundational assumption of the modern world itself- the "Copernican Principle".

One of the leading concepts in this development of cosmology is so-called "void cosmology".

Void cosmology is simply an intellectually acceptable term for what amounts to "weak" geocentrism.

It places the Earth near the center of a "void", an under-density of matter, and in so doing accomplishes two interesting things:

We know that "dark energy" exists only because of observations of Type 1a Supernovae, which are interpreted to mean that the universe must be accelerating in its expansion.

Needless to say, if the universe is accelerating in its expansion, then something must exist which is able to counteract the attractive force of gravity.

That something is completely unobserved, and exists only as a term in an equation.

But it is often treated in the scientific pop press as an ontological reality, and it is bandied about as if it were a substance about which our science is prepared to tell us many important things.

The one truly important thing about this non-existent substance is that it is non-existent; that is to say, it does not exist except as a mathematical term.

The term must exist in order to save the otherwise unsalvageable mathematical expressions of Standard Model cosmology, but it has no other necessary existence.

If the Standard Model is wrong- say, for example, if its foundational assumption of a Copernican/cosmological Principle is wrong- then dark energy exists henceforth not even as a mathematical term, but instead merely as a fictitious fudge factor, an immortal example of how to bungle science by imposing upon observations a magical "fixer upper", so as to render them amenable to one's assumptions.

Recently, the anisotropy of cosmic acceleration has at tracted great attention, which may be caused by the non- trivial cosmic topology or some residuals of observational errors. In this paper, by using the Union2 SNIa dataset at different regions in the whole sky, we investigated the dependence of cosmic acceleration on the directions in the Galactic coordinate system, where the deceleration parameter q0 has been used as the diagnostic to quantify the anisotropy level.

In the anisotropic q0-maps, we find the significant dipole effect with the amplitude A1 = 0.466, whichdeviates from zero at more than 2-σ level. This study also shows that the direction of the dipole trends to be perpendicular to CMB kinematic dipole. The best-fit dipole direction is (θ = 108.8◦, φ= 187.0◦), and the angle be- tween this direction and that of CMB kinematic dipole is 95.7◦. We find the perpendicular relation between these two dipoles is anomalous at the 1-in-10 level........

Recently, the new release of the Planck observations on the CMB temperature anisotropy confirmed the alignment of the CMB quadrupole and octupole. And this particular direction is nearly aligned with CMB kinematic dipole direction [59]. At the same time, the discontinuous distribution of power in the hemispheres on the sky was also been confirmed. All these show that we have the evidence for a break in isotropy. In order to solve these problems, a phenomenological dipole modulation may be needed [59, 60]. Since all these directional anomalies, as well as the alignment problems of the cosmic acceleration anisotropy discussed in this paper, the parity asymmetry of CMB power spectrum [47], the large-scale velocity flows [49] and the large scale alignment in the QSO optical polarization data [51] are connected with the CMB kinematic dipole and/or the ecliptic plane. We expect a single dipole modulation mechanism could solve all these puzzles.

Several works have suggested that this kind of modulation could be caused by the non-trivial topology of the Universe, such as the anisotropic global Bianchi VIIh geometry [61], the Randers-Finsler geometry [62], or the multi-stream inflation [63]. However, if they have the cosmological origin, it is very difficult to answer: Why the special direction is related to the current motion di- rection of the Earth, i.e. the CMB kinematic dipole.So, in our view, we would rather believe that these problems should be caused by some unsolved systematical errors in observations or data analysis."

But of course you would rather believe this.I appreciate the precision of that sentence."We would *rather* believe..........."It sets the stakes in proper perspective in this rapidly- expanding debate over the Copernican Principle.